Recently, in the field of photographic processing service, a high-image-quality light-sensitive material that can be rapidly processed, is desired as a part of improving service to users in order to reduce, for example, customer's waiting time, and also as means of increasing production efficiency. For this purpose, several technologies have been proposed using silver halide grains having a high silver chloride content, so-called "high silver chloride grains," which means silver halide grains having a silver chloride content of 80% or more (hereinafter referred to as high silver chloride grains). The use of high silver chloride grains gives such advantages as that developing speed is accelerated, and the reusability or recycling property of a processing solution is increased. Presently, a light-sensitive material of the type using high silver chloride grains is dominant in the light-sensitive materials for print, such as color photographic printing paper. A processing system in which a light-sensitive material containing a high silver chloride emulsion is processed at a color-developing time of 45 seconds, and a total processing time of less than 4 minutes, is generally used (for example, the color processing system CP-45X, tradename, manufactured by FUJI PHOTO FILM CO., LTD.). However, it is difficult to say that the level of total processing time required for such a system is wholly satisfactory, compared with other color systems (for example, an electrostatic transfer system, a thermal transfer system, and an inkjet system). There is a demand for ultra-rapid processing at a level in which the total processing time is less than 1 minute.
In order to achieve the above-described ultra-rapid processing, various kinds of investigations have been carried out with respect to two aspects: the processing solution and the light-sensitive material.
In order to achieve ultra-rapid processing, it is necessary to shorten each of steps of 1 color development, 2 bleach-fixing, and 3 washing/stabilization. With respect to color development, some attempts have been made, such as use of high temperature, high pH, and high-concentration color-developing agent. Further, addition of additives, such as a development accelerator, is also known. Examples of the development accelerator include 1-phenyl-3-pyrazolidone, described in British Patent No. 811,185; N-methyl-p-aminophenol, described in U.S. Pat. No. 2,417,514; and N,N,N',N'-tetramethyl-p-phenylenediamine, described in JP-A-50-15554 ("JP-A" means an unexamined published Japanese patent application). However, satisfactory rapidity cannot be achieved by these methods. Rather, deterioration of properties, such as increased fogging, often occurs.
Further, some attempts have been made to reduce bleach-fixing time, that is, making desalting to be rapid, by use of such as high-temperature, low pH, and high-concentration bleach ingredients. However, some problems occur, such as that the stability of a bleaching solution deteriorates, that cyan dye density is lowered by reduction of the cyan dye to a leuco base (Blix discoloration), and that insufficiency of washing bleach ingredients (primarily an iron salt of ethylenediamine tetracetic acid, and the like) occurs.
Further, at the step of washing, usually the final bath is replenished, and countercurrent-type multistage washing is used. Further, it is practically carried out to improve efficiency of washing by reducing the salt density in water using an ion-exchanged water, and/or by increasing the temperature of washing water. However, even though rapidity has been achieved to some extent, there are still many insufficiencies, in that an irradiation neutralizing dye, a sensitizing dye, a developing agent, ingredients of a Blix processing solution, and the like are sometimes incompletely washed out due to a shortage of processing time.
On the other hand, from the viewpoint of a light-sensitive material having ultra-rapid processing suitability, investigations have been made with respect to the use of a high-activity coupler and a coupler having a high extinction coefficient, reducing the amount of gelatin, and the like. However, the present existing light-sensitive materials fail to satisfy various properties required for a light-sensitive material.
Further, JP-A-7-239538 and JP-A-7-239539 describe that a silver halide emulsion layer containing a yellow coupler is coated on the same side but further from (apart from) a support than at least any one layer of a silver halide emulsion layer containing a magenta coupler and a silver halide emulsion layer containing a cyan coupler, each being coated on the support, to thereby achieve advance in color development speed. However, according to the method described in these publications, there are such disadvantages that fog stripes of an emulsion at the yellow-coloring layer are induced by pressure when processed using a roller conveyance type autoprocessor, processing color contamination becomes worse, or a cyan-colored density is lowered by Blix discoloration. Accordingly, further advanced technologies have been required. Further, there is also such a problem that at the time of processing by means of a roller conveyance type autoprocessor, if a curl of the light-sensitive material is large, formation of the fog stripes becomes larger.
Meantime, the high silver chloride grains having an excellent rapid processing suitability tend to form grains whose exterior faces (planes) are {100} faces (hereinafter referred to as {100} grains) under usual production conditions. In fact, the practically used grains are cubic. Recently, tabular {100} grains having a large specific surface area (the ratio of a surface area to a volume), thereby enabling an effective spectral sensitization, have been developed. Examples of these tabular grains are disclosed in, for example, U.S. Pat. Nos. 5,320,938, 5,264,337 and 5,292,632.
However, the high silver chloride {100} grains have a problem that they are easily fogged, when compared to commonly used silver bromide grains. In order to overcome this problem, the use of high silver chloride grains whose exterior faces are {111} faces (hereinafter referred to as {111} grains) has been proposed, as disclosed in JP-A-6-138619.
Special means are necessary to produce the high silver chloride {111} grains. In U.S. Pat. No. 4,399,215, Way discloses a method of producing high silver chloride tabular grains, which comprises using ammonia. However, it was difficult to produce practically useful small size grains by this method which comprises using ammonia, thereby producing silver chloride grains having high solubility under the conditions of higher solubility. Further, this method has a disadvantage that fogging easily occurs because the pH at the time of the production is as high as 8 to 10. In U.S. Pat. No. 5,061,617, Maskasky discloses high silver chloride {111} type grains produced using a thiocyanate. The thiocyanate increases the solubility of silver chloride as well as ammonia. There are known methods of adding additives (crystal habit controlling agents) at the time of the grains formation in order to form high silver chloride grains whose exterior faces are {111} faces, without increasing solubility thereof. These methods are listed below:
crystal habit controlling Patent No. agent Inventor U.S. Pat. Azaindenes + thioether Maskasky No. 4400463 peptizer U.S. Pat. 2-4-diazolidinon Milune et al. No. 4783398 U.S. Pat. Aminopyrazolopyrimidine Maskasky No. 4713323 U.S. Pat. Bispyridinium salt Ishiguro et No. 4983508 al. U.S. Pat. Triaminopyrimidine Maskasky No. 5185239 U.S. Pat. 7-Azaindole-seris compound Maskasky No. 5178997 U.S. Pat. Xanthine Maskasky No. 5178998 JP-A-64- Dyes Nishikawa et 70741 al. JP-A-3- Aminothioether Ishiguro 212639 JP-A-4- Thiourea derivative Ishiguro 283742 JP-A-4- Triazolium salt Ishiguro 335632 JP-A-2-32 Bispyridinium salt Ishiguro et al. Japanese Monopyridinium salt Ozeki et al. patent application No. 7-146891
As shown above, development of such techniques was made.
The tabular grains are preferred for spectral sensitization from the viewpoint that they have a high ratio of surface area to volume (specific surface area), so that they can absorb a large amount of a spectral sensitizing dye. On the other hand, washing out of the sensitizing dye becomes the more difficult, so that the problem of coloration due to the sensitizing dye remaining after the processing (remaining (or residual) color) becomes serious.
Techniques of improving these problems in which {100} high silver chloride grains and {111} high silver chloride grains are involved, are disclosed in U.S. Pat. No. 5,674,674, and Japanese Patent Application No. 10-123789, respectively. However, there is a demand for techniques of enabling more rapidly to wash out the sensitizing dye, to thereby control fogging due to remaining color.
Further, in order to improve an ultra-rapid processing suitability in color photographic light-sensitive materials, the following means can be mentioned: 1 Employment of a highly activated coupler; 2 Reduction in a coating amount of organic materials owing to, for example, the employment of a coupler which forms a colored dye exhibiting a large molecular extinction coefficient; 3 Reduction in a coating amount of a hydrophilic binder and Enhancement of a thin layer for the total of isphotographic constitutional layers, due to 2; and 4 Employment of a silver halide emulsion exhibiting a high developing speed. In order to improve the suitability of a light-sensitive material to advances in an ultra-rapid processing speed in color development and desilvering, such an effort has been made in this technical field that reduction in a coating silver amount of a light-sensitive material is carried out by, for example, the employment of a coupler which forms a dye exhibiting a high molecular extinction coefficient. Further, it is known that an advantage to rapidity of development can be also obtained by coating a silver halide emulsion layer exhibiting the largest average grain size (the yellow coupler-containing layer of conventional many color printing materials corresponds to this layer) in the position farther-most from a support among light-sensitive emulsion layers. This advantage can be attained by the methods as described in, for example, JP-A-7-239538 and JP-A-7-239539.
On the other hand, in the bleach-fixing processing, when a bleach-fixing solution having a low pH value is used in order to enhance advances in desilvering speed, a dye formed by a cyan coupler tends to become a colorless leuco dye, which results in reduction of a cyan density (this phenomenon is hereinafter called a blix discoloration). After processing, the leuco dye is oxidized by oxygen in the air and gradually returns to an original cyan dye in several months (leuco dye reciprocity). This means that a color balance just after the processing gradually breaks, and consequently the image quantity is deteriorated.
As an improved technique to prevent a light-sensitive material from the blix discoloration, known are method of improving the blix discoloration by the use of dispersion oils exhibiting a high viscosity, and the use of specific hydroquinone compounds or quinone compounds, as described in, for example, JP-A-3-144442 and JP-A-2-267548, or the use of a cyan coupler dispersion containing a high boiling organic solvent together with a water-insoluble and organic solvent-soluble polymer, as described in JP-A-2-43541. Further, JP-A-9-171240 and JP-A-9-329861 each describe a method of improving the blix discoloration by the incorporation of specific water-soluble polymers or polymer latexes into a cyan coupler-containing layer.
Further, for example, JP-A-3-144442 describes that the blix discoloration can be improved by a method of dispersing a coupler in a coupler solvent exhibiting a relatively high viscosity, and adjusting the average grain diameter of the resulting emulsion dispersion to a relatively large region. However, it is known that even this method causes reduction in colorability as a reverse effect on increase in the average grain size.
As described above, methods of improving the blix discoloration has been investigated up to now in this field of technology. In the present time, the conventional methods however are not satisfactory under such circumstances that processing conditions are becoming more and more severe, such as a processing with a bleach-fixing solution exhibiting a low pH value by which the desilvering speed could be enhanced, and increase in the accumulated density of a color-developing agent owing to a low replenishment.
Conventional silver halide color photographic light-sensitive materials (hereinafter referred to as a light-sensitive material according to the occasion) have several problems from the viewpoint of obtaining a high quality image, when a processing time is reduced. That is, when the conventional light-sensitive materials are subjected to a color developing process and desilvering process for such a short time as about 10 seconds respectively, a satisfactory coloring density cannot be obtained, and improvement in the blix discoloration is difficult to reach a satisfactory level.
For the object to obtain a high coloring density among the above-described problems to be solved, it may be effective means to use a layer structure in which a silver halide emulsion layer exhibiting the lowest speed of development is positioned over the other silver halide emulsion layers, and/or to render the total of photographic constitutional layers thinner. However, our investigation has made clear that the layer structure in which among a yellow-coloring silver halide emulsion layer, a magenta-coloring silver halide emulsion layer, and a cyan-coloring silver halide emulsion layer, the yellow-coloring silver halide emulsion layer, which contains a silver halide emulsion exhibiting the largest average grain size, is positioned farther-most from a support (i.e., as an upper layer of the other two light-sensitive emulsion layers), provides a relatively high coloring density even when the color developing time is reduced, but on the other hand it causes such a problem that the blix discoloration becomes worse.